With Workbench 2.x and newer, with the needed kickstart ROM version, you indeed get CrossDos for reading / writing PC floppies. If your Amiga is an 1.3 version then you'll have to dig deep into the internet. With the remaining problem of: How to get the piece of software found on Aminet (probably with the PC) onto your Amiga? And that's how your question started :-).
If you indicate your country of residence, fellow countrymen/countrywomen might be able to help you with an Amiga floppy with all the Aminet programs needed to get you going.
Or buy a Catweasel ;-)